That's a fair question, and it's a common experience — the trick is to separate "how do I evaluate this?" from "do I trust you?", because those are two different conversations.
Start by asking for specifics rather than yes-or-no answers. For each item, ask three things: what exactly did you measure, what's the number, and what happens if I wait? A real finding usually comes with data — tire tread in 32nds of an inch, brake pad thickness in millimeters, a battery test printout with cold-cranking amps, a photo of a leaking seal. "Your brakes are getting low" is not the same as "your front pads are at 3mm, the minimum is 2mm, and you'll likely hear metal-on-metal within a few months." The second version tells you how urgent it actually is and lets you judge for yourself.
Second, ask to see it. Most shops today do digital inspections with photos or video, and many will walk you out to the car or show you the old part. A shop that's confident in its findings is usually happy to show you. If they won't, that itself is information — but it isn't proof of anything, since some shops are just busy or poorly organized.
Third, sort the list into categories yourself. Safety and drivability items (brakes, tires, steering, suspension play, lights, active leaks) deserve attention soon. Maintenance items with a mileage interval (fluids, filters, spark plugs) can almost always be scheduled rather than done on the spot. Comfort and "while we're in there" items (cabin air filter, wiper blades, fuel induction cleaning) are the most commonly pitched and the easiest to defer.
Fourth, check your owner's manual's maintenance schedule. It's the manufacturer's baseline, and it's free. If a recommendation isn't on it or is being pushed far ahead of schedule, ask why your driving conditions justify it — sometimes there's a good answer (lots of short trips, dust, towing), and sometimes there isn't.
Finally, the wording that keeps it friendly: "I appreciate you flagging these. I'm watching my budget this month — can you help me prioritize which of these truly can't wait and which can go another few thousand miles?" Then ask them to note the declined items on the invoice. That's not distrust; it's a record, and it protects both of you. For anything expensive — a transmission concern, a big suspension quote — a second opinion is normal and no reasonable shop takes offense.
Over a few visits you'll notice a pattern: if the same "urgent" item never becomes a problem, or every single visit produces three new findings, that's a signal worth acting on.
